Automatic car-brake.



Patanted Nov. 6,1900; B. S. 'LAWSUIL AUTOMATIC CAB BRAKE.

(Application filed. Feb. 20, 1900.)

3 Sheets-Sheet l.

m. M5345. Patehted Nov; 6, I900; B. s. LAWSON.

AUTOMATIC CAB BRAKE.

(Application filed Feb. 20, 1900.)

3 Shaw-Shoat 2.

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Patented Nuv. '6, I900.

No. 66L345.

B. S. LAWSON. AU'TOMATlC CAB BRAKE.

(Application filed Feb. 20, 1900.)

.3 Sheeta$heat 3.

(No Model.)

n2 norms. PETERS cu. FHOTO-LITMQ, WASHINGTON. o c.

MM T i l lfi BENJAMIN S. LA\VSON, OF NEW YORK, N. Y., ASSIGNOR, BYDIRECT AND MESNE ASSIGNMENTS, OF ONE-HALF TO DAVID W. COPELAND AND HENRYJ. HART, OF SYRACUSE, NE\V YORK.

AUTOMATlC CAR-BRAKE.

SPECIFICATION forming part of Letters Patent No. 661,345, dated November6, 1900.

Application filed February 20, 1900. Serial No. 5,869. (No model.)

To all whom it may-concern.-

Be it known that I, BENJAMIN S. LAWSON, a citizen of the United States,residing in the borough of Brooklyn, in the city and State of New York,have invented a certain new and useful lmprovementin Self-Acting Brakesfor Railroad-Cars; and I do hereby declare that the following is a full,clear, and exact description thereof.

The improvement applies to that class of brakes in which a piston iscaused to move in a cylinder by the pressure of a fluid and actingthrough connected mechanism puts on and lets off the brakes. I canoperate with air, but prefer a liquid, and will describe the inventionas operating with oil. I operate a pump by the rotation of one of theaxles, con necting the pump-frame to the same axle, so that it willpartake of the same rising and sinking motions. The pump may workconstantly; but in the most complete form of the invention such does nottake place, because the valves do not operate, the piston being allowedto play idly in the pump-cylinder and the oil moving freely with it,while the induction-valves and the delivery-valves all rest undisturbedupon their respective seats. A single easily-moved valve controlled bythe attendant determines whether this idle condition or the fully-working condition shall obtain.

The following is a description of What I consider the best means ofcarrying out the invention.

The accompanying drawings form a part of this specification.

Figure 1 is a longitudinal vertical section through the novel parts onthe line 1 l in Fig. 2, some of the other portions of the car being seenin elevation. The wheels are in dotted outline. Fig. 2 is a plan View.The remaining figures are on a larger scale. Fig. 3 is a side elevationwith certain portions in vertical section. Fig. 4 is a correspondingplan view. Fig. 5 is an end elevation as seen from the right in Fig. 3.A portion is sectioned on the line i 4 in Fig. 3, seen from the right.Fig. 6 is a horizontal section on the line 6 6 in Figs. 3 and 5. Figs.'7, 8, 9, and 10 are sections on the lines correspondingly numberedinFig. 6. Fig. 7 is a longitudinalsection on the line 7 '7. Fig. 8 is acorresponding section on the central line 8 8. Fig. i) is acorresponding section on the line 9 Fig. 10 is a transverse verticalsection on the line 10 10. Fig. 11 is a corresponding section on theline 11 11.

Similar letters of reference indicate like parts in all the figureswhere they appear.

A is the truck-frame, having the body of a car supported thereon bysprings. (Not shown.) The attendant COIlll'OlS the brakes through eitherof the upright shafts mounted in the ordinary positions and turned,held, and released in the ordinary manner at will.

B are the ordinary carrying-wheels, set on axles B B, running inaxle-boxes carried in jaws A in the truck, with liberty to rise andsink, subject to springs, (not shown,) all in the ordinary andlong-approved manner.

N is an upright shaft operated by the brakeman standing on the platformthrough an ordinary hand-wheel. (Not shown.)

N is an ordinary chain operated by turning the shaft.

N are rods which form practically continuations of the brake-chain.

C is a pump-frame made in separable parts embracing one of the axles Band carrying slideways C, usually termed slides, and a nicely-boredpump-cylinder 0 having two ports 0 and 0 leading upward from the ends.

D is the induction-valve, and E the delivery-valve serving the port 0.Assuming the car to be moving from left to right, these will be at therear end of the pump. Corresponding valves D and E serve the port 0 atthe forward end of the pump. These valves rise and sink and performtheir usual functions when required to apply the brakes, but during thegreater portion of the time-all the time when the car is running freelyalong the track-the valves are idle.

C is my brake-cylinder cast in one with the frame C. It is closed at oneend, the right, as shown; but the other end, the left, has only apartial head of annular form, the large central opening having astuffing-box matching on a tubular or trunk extension M from a largerpiston M, arranged to Work in the ordinary tigh t-fitting manner in thebrak ecylinder C There is a port 0 leading upward from the right end ofthis cylinder. When oil is forced down through this port 0 it urges thepiston M to the left, and this, acting through the stout rod 0, operatesthe brake-beams P,connected by rods and levers, as usual, and pressesthe brake blocks P strongly upon the wheels B and rapidly arrests themotion of the car. The brakes may be applied with all the force due tothe strong action of the pump and released again by a simple and easymovement.

0 is what may be termed a controllingcylinder, cast with or fixedrigidly to the frame 0, closed at each end. Its inner surface is boredtruly cylind rical,except for three circular channels or zones f, f andf communicating, the left one f with the left port a and the right one fwith the right P011102. The duty of the middle zone f may be neglectedfor the present. Let us study the effect of the other zones and thesliding rings, which are slightly wider.

Then the operator turns the brake-shaft at either end of the car, heacts through a belt or pitch-chain and lever to move the rod I lying inthe axis of the brake-cylinder and has to carry two rings I and I fixedon such rod. Turning the brake-shaft in the proper direction to releasethe brakes of an ordinary hand-operated system moves the rod I and therings I and I to the right, so that the rings uncover the zones andallow any oil rising through the port 0 to flow freely upward and inwardthrough the zonef' into and along in the controlling-cylinder and outthrough the zone f into the port 0 and through the latter down into theright end of the pump. The controlling-cylinder and the ports thusconditioned constitute a free communication between the ends of thepump. When the pump-piston G is, by the eccentric B and the connection GG carried to the left, the oil moves upward in the port 0, then to theright through the controlling-cylinder O and downward through the port 0Whenimmediately afterward the pump-piston G moves to the right, the oilmoves upward through the port 0 then in the reverse direction through Cand down through the port 0. This is the condition under which the carusually works, subject to no resistance from my apparatus beyond aslight friction. When the car is moving at full speed and thepump-piston making its heretofore-idle reciprocations rapidly, theattendant shifts the brake-wheel or brake-handle in the proper directionto apply the brakes, (the same motion which he is accustomed to with thehandbrakes.) He shifts the rod I, and correspondingly the rings I and 1so that the rings cover each its proper zone. The passage through thecontrolling-cylinder is completely stopped. Now the reciprocations ofthe pump-piston become effective and the device works as a pump, theinduction-valves D D and the delivery-valves E E rising and sinking inthe long-known manner and with the long-known effect. Each movement ofthe pump-piston G to the left drives the oil from the left end of thepump-cylinder 0 up through the port 0, as before, and as it cannot gointo the controlling-cylinder, as before, and cannot resist the impulsereceived from the powerful motion of the piston G it compels thedelivery-valve E to rise and the full charge of the pump passes upthrough the passage thus opened. Thence it moves downward under thestrong pressure induced by the pump through the port a into thebrake-cylinder 0, moving the brake-piston M strongly to the left, andthrough the rod 0 forcibly operating the brake-beams P and putting onthe brakes.

Oonfining our attention to the left end, each movement of thepump-piston Gr to the right draws oil from a small reservoir G which oildescends through a passage 0 (see Figs. 3, l, and 5) into a chamber a,and thence rises through the ind notion-valve D and descends through thesame port 0. The action of the two ends of the pump are alike,alternating.

.Both force the brake-piston M in the same directionto the left. Eachdelivers into a chamber communicating with the same end of thebrake-cylinder through the same port a.

The pump need not be large to put the brakes fully on in a very fewrevolutions of the car-wheels. It will often be the case thatthevelocity of the car is too great to be stopped in so short a distance.If it is desired to stop the wheels and have them slip on the track, thebrake-cylinder and piston may be made sufficiently large to effect this.It is preferable not to slip the wheels, but to have themretarded'nearly enough to efiect that. To attain this, I provide aspringloaded relief-valve R with provisions T for adjusting the tensionof the springs. After the brake has been properly put on the oilovercomes the adjusted load and raises the valve R and discharges idlyinto the reservoir G the oil pumped during the last part of the slowingmotion. The return movement of the brake-piston M is efiected by the aidof a spring L, coiled around the trunk M and urging the piston towardthe closed end of C It is important to provide for the ready escape ofthe oil which has filled the brake-cylinder after its dutyis performedand it is released from the action of the pump. The function of themiddle zone f is to facilitate this. This middle zone of thecontrollingcylinder is in free communication with the reservoir 0 Themiddle ring 1 keyed or otherwise firmly set on the rod I, covers thatzone and makes it of no effect during the period while the brake is on,but when the rod I and its attached rings are again moved to the rightin letting off the brakes this zone is uncovered and the oil, which hasbeen under pressure in thebrakecylinder, is put into free communicationwith the reservoir, and it retreats as required by the return motion ofthe brake-piston.

A pipe 0 Figs. 1, 2, 4, and 6, forms the connection between port 0 andthe reservoir to allow the oil to descend from the latter and reach theinduction valves when the brake is put on. The same pipe allows thereflow of the oil back to the reservoir when it is forced out throughthe relief-valve R.

A separate pipe G, Figs. 1, 2, 4, and 8, constitutes the connectionbetween the controlling-cylinder 0 and the reservoir C to provide forthe idle flow of the oil back to the reservoir when the brake isreleased.

I claim as my invention- 1. In a car-brake actuated by fluid-pressure,the contiuuously-reciprocating piston G playing in a cylinder 0 withports whereby the fluid may play idly from one end of such cylinder tothe other alternately in opposite directions and a brake-cylinder,piston and connections for operating the brakes, and ports,valves and acontrolling device, whereby the fluid can be thus moved idly or directedinto the brake-cylinder at will, all combined and arranged substantiallyas herein set forth.

2. In a car-brake actuated by fluid-pressure, thecontinuously-reciprocating piston G playing in a cylinder 0 having ports0 0 in combination with induction valves D, D serving with asupply-reservoir C deliveryvalves E E serving with a brake-cylinder Oand a piston M in the latter, and proper connections therefrom to thebrake devices I and with a controllable valve device serving to put thetwo ports in free communication and thus allow the fluid to reciprocateidly at will or to close such communication and cause the fluid to bepumped and thus to apply the brakes and with the screw-threaded guidingand adjusting case T inclosing a relief-valve R and a helicaloperating-spring, all substantially as herein specified.

3. In a car-brake actuated by fluid-pressure, thecontinuously-reciprocatin g piston G playing in a cylinder 0 havingports 0' 0 in combination with induction valves D D serving with asupply-reservoir C deliveryvalves E E" serving with a brake-cylinder Cand a piston M in the latter and proper connections therefrom to thebrake devices Pand with acontrollable valve device comprising thecylinder C with its zone f f and the rod I with its rings I I serving toput the two ports in free communication and thus allow the fluid toreciprocate idly or to close such communication at will and cause thefluid to be pumped and thus to apply the brakes all substantially asherein specified.

In testimony that I claim the invention above set forth I affix mysignature in the presence of two witnesses.

BENJAMIN S. LAWSON.

Vitnesses:

WILLIAM PAXTON, M. F. BOYLE.

